Various containers for the storage of food, both liquid and dry are well known. Present day food containers, particularly those utilized for household storage applications display a wide variety of forms, closure systems, seals, and materials dedicated to the short term storage of a variety of dry and liquid foods. With the advent of newer plastic materials having improved properties better suited to meeting the standards and criteria of food container safety, as mandated by FDA standards, higher temperature stability, and the necessary structural requisites of flexibility or stiffness as may be required by individual design, a proliferation of food containers of all types has been made available to the consumer.
The majority of these containers however display critical functional inadequacies and drawbacks in respect to easy opening and closing while attempting to maintain a watertight seal in a closed mode. In general, the tighter the cap or lid seal fits the container, the greater the force required for its removal. The negative implications of this judged in terms of known consumer desires and preferences for a simple easy to remove or operate cap or lid while at the same time having the assurance of a watertight seal are readily apparent.
The implications of such containers and their limited degree of operability are especially pointed in the case of the elderly, those who suffer from arthritis, others who suffer from some degree of motor impairment, and children.
Reusable food storage containers for the short term storage of liquid or dry foods, i.e. juices, cereals, meal leftovers, etc. may be classified into five groups. In the first group are those containers which have a simple interference fit lid. An example of such a container would be commercially available plastic ice cream containers, where consistent water tightness is not required. A second, well-known group utilizes screw-on type lids or caps, often provided with a species of elastomeric seal to provide water tightness. A third group relates to a combination form of the preceding groups in that a screw-top or snap-type lid is used in conjunction with an integrally molded pouring spout provision. A fourth classification embraces container types that depend upon a flexible lid that incorporates an instanding, positive continuous seal contour that engages and locks into a matching negative groove on the container lip. The fifth group consists of containers utilizing a plug-type of closure not always, but often, in conjunction with an elastomeric seal to promote water tightness.
U.S. Pat. No. 4,813,570, discloses a container with a removable lid, the container having a side wall at the top of which there is provided an outwardly projecting bead or bead portions abutted by the lid, wherein the lid has a skirt with downwardly and/or inwardly facing cams. The container disclosed is said to enable a person with a handicapped hand or impaired vision to remove the lid from the container in a controlled manner such that the user is able to control the lid and/or container so that they do not suddenly slip from the user's grasp during the removal of the lid.
Despite the presence of these various forms of containers, there exists a need for an easy opening, substantially liquid-tight container which overcomes the negative aspects and disadvantages of prior art containers and lid functions.